Differential fiber dispersing rolls and felting therefrom



May 24, 1966 w. J. `OJA l 3,252,186

DIFFERENTIAL FIBER DISPERSING ROLLS AND :E'ELTNG v THEREFROM Filed Jan.21, 1963 `4 sheets-sheet 1 h nvenor Wayne J' Qja W. J. OJA

` May 24, 1966 4 Sheets-Sheet 2 Filed Jan. 21, 1965 INVENTOR. Z/ayne.7.' Qj'a B YM. mmw,

Jzarqy May 24, 1966 w. .1. OJA 3,252,186

DIFFERENTIAL FIBER DISPERSING ROLLS AND FELTING THEREFROM Filed Jan. 21,1965 4 Sheets-Sheet 5 54X@ @Lf-650 INVENTOR.

wayne .I Qja May 24, 1966 w. J. oJA 3,252,186

DIFFERENTIAL FIBER DISPERSING ROLLS AND FELTING THEREFROM Filed Jan. 21,1963 4 Sheets-Sheet 4 y r 64a 64 7 6i A a 67 63 g INVENTOR.

Wayne I Qja BYa United States Patent O 3,252,186 DIFFERENTIAL FIBERDISPERSING ROLLS AND FELTING THEREFROM Wayne J. Oja, Cloquet, Minn.,assignor to Wood Conversion Company, St. Paul, Minn., a corporation ofDela- Ware Filed Jan. Z1, 1963, Ser. No. 255,422

4 Claims. (Cl. 19-156.3)

This application is a continuation-in-part of application Serial No.767,050, filed October 1, 1958, now abandoned.

The present invention relates generally to dispersing fibrous materialfor various purposes, such as felting, and to apparatus therefor.

In making felts by collecting fibers from a dispersion thereof in air,there are mechanical difiiculties in forming and maintaining the desireddegree of individualization yof the fibers and also continued uniformityof dispersion so that in collecting the fibers as a felt on a movingconveyer .a uniform felt is produced.

The present invention provides a mechanical disperser for dischargingfibers for felting, or for other uses :of a dispersion. Preferably, sucha disperser is most useful to discharge into a chamber or other space toform a stream which expands from the delivery end of the disperser. Thisis in icontrast to delivering dispersed fibers into a conduit forconveyance, in which conduit clotting is induced.

It is an object of the invention to provide a first-toothed rotor toreceive and hold fibrous material, and to provide in combinationtherewith a second and intermeshing toothed rotor of which the teethrake through the teeth of the first rotor.

It is a further object of the invention to employ such a disperserhaving differential peripheral-speed rolls as the feeder of dispersedfibers to a fiber-collecting member for forming a felt.

Various other and ancillary objects and advantages will become apparentfrom the following description and explanation of several embodiments ofthe invention i1- lustrated in the accompanying drawings, in which:

FIG. 1 is a cross-section of dispersing rotors in a housing whichdischarges fibers and air from the rotors into a depositing chamber toform a felt on an endless conveyer which when foraminous may move over asuction box.

FIG. 2 is `a plan view of two rotors each having two sets of plates onewith projecting fingers so arranged as' to intermesh with fingers of theopposite rotor.

FIG. 3 is a cross-section taken on the line 3-3 of FIG. 2.

FIG. 4 is a fragmentary plan view of a felting chamber in which rotorsof the present invention are mounted.

FIG. 5 is a vertical cross-section of a chamber such as indicated inFIG. 4.

FIG. 6 is a cross-section of two intermeshing rotors similar to those ofFIG. 3, but modified so that the projecting fingers are swinginghammers.

FIG. 7 is a fragmentary cross-section taken on the line 7-7 of FIG. 6.

In general, the disperser involves two rotors having parallel axes, eachwith an axial roll or mandrel from which a multiplicity of elementsprojects. The elements of the two rotorsvare arranged to intermesh orby-pass during rotation, and in certain types of rotors, they are soconstructed and arranged that the ends of the elements of each rotorjust cle-ar the periphery of the axial roll or mandrel of the other in amanner to prevent accumulation of fibrous material at the periphery ofthe roll. In operation, the rotors turn in opposite directions, thereby3,252,186 Patented `May 24, 1966 ICC providing a receiving nip forfibrous material to be individualized within the space of theintermeshing elements for discharge of a dispersion of fibers from theother side of the nip.

In order to accomplish the desired result, one set of elements rakesthrough the other, and to that end the raking set has the greaterperipheral velocity. When the rotors .are duplicates in structure onemust rotate at a higher speed. In a case where the raking rotor has alarger diameter than the other, the difference in size may be such thatthey can revolve at the same or different angular velocities. For thebest results, the greater the differential in peripheral velocities ofthe rotors, the better the dispersion and the greater the production.

Consider two identical rotors rotating at identical speeds, eachprovided with projecting elements intermeshing and by-passing asdescribed. In such case the elements of each rotor pass through theelements of the other, crossing in the middle, each set raking throughthe other in the direction of movement into the nip. Where fibrousmaterial is fed to such a nip it is more fed through the nip thandispersed, although there may be a slight degree of dispersion. Thepresent invention contemplates that only one set of elements rakethrough the other set in the direction of movement through the nip. Theaction may be visualized by considering one rotor as stationary and theother rotating to rake through it. When a mass of fibrous material isplaced in the nip it will be picked away by the rotating rotor anddispersed until the mass is gone. By continuously rotating the supposedstationary rotor, slowly relative to the said moving rotor so as tomaintain the same raking action, the process may be made continuous.revolved while maintaining the same relationship, the greater is the-capacity of the two rotors to disperse.

In operation, the speed of the slower rotor in part predetermines therate of feed for a given result, but in so doing, it calls for a greaterspeed of the faster elements as the speed of the slower elements isincreased.

The character of the intermeshing elements may vary widely in accordancewith the type of fibrous material fed into them.. For loose bulks offibers the elements may be long and flexible, like brush bristles. Forfelting pulp laps and other dense fibrous material, the elements may bestrong and rigid ones, unyielding in their relation to the mandrel orroll which carries them.

The elements on each rotor may be in ordered or unordered arrangement.In the case of rigid elements, whether fixed relative to their mandrel,or movable peripherally relative thereto, like swinging hammers, theymust be arranged to avoid destructive collisions in rotating. Where theelements are relatively long and flexible and rigidly mounted, they maystrike and pass each other in rotation, as described hereinafter withreference to FIG, 1.

FIG. 1 shows a deposition chamber 71 which may be open at the top, andwhich has end Walls 72 and 73. Through the bottom of the chamber passesan endless fiber-collecting conveyor 74, running over roll 75 outsidethe chamber. A fiber mat 76 is shown as a felt formed on the conveyor,the first fiber depositing in the vicinity of location 77, and the lastfibers depositing in the vicinity of location 78. End wall 72 terminatesjust above conveyor 74 and end Wall 73 terminates well above theconveyor 76 and is provided with an adjustable extension or gate 73which is positioned to terminate just above the particular felt 76 beingformed.

When suction is desired to assist in the felting operation, the conveyor76 is made foraminous, for example, being a woven wire screen, beneathwhich is a suction box 80 connected by conduit 81 to a suction fan 82.The suction area has an extent indicated by the locations 77 The fasterthe two rotors are dispersed fibers in -a stream of air.

and 78, because when suction is employed it predetermines theselocations.

Fiber-dispersing means is provided within a housing S4 having `closingside walls and an open entrance end 8S and open exit end 85. Housing 84is located near the top of the deposition chamber and well above theconveyor 74 to allow spreading of the stream discharged from thehousing. As shown, the housing projects into a large opening 71 in thetop wall 71a of chamber 71, the portions of the opening 71 laterally ofthe housing serving to vent air from the chamber when suction is notemployed. v

At the open top 85 of the housing means is provided to feed fibrousmaterial to be dispersed for felting, and means to feed other materialto be deposited with such fiber, which other material may be a secondkind of fiber or material such as a powder form of binder which can beactivated by heat in the felt 76.

A fiber feeding means is shown in the form of an endless.feeding belt 86running over pulley 87. Fed fiber is indicated at 88. A second feeder isshown as endless belt 89 running over pulley 90, and feeding, forexample, thermosetting resin powder 91 into the housing 84.

In the housing there is at least one set of dispersing rotors, andpreferably'two sets, which are constructed, positioned, and operated sothat as they disperse fibrous material 88, they also draw in air so asto discharge the This air can be vented largely at the open areas 71when suction is not employed, and when suction is employed the openareas may be sealed off by moving gates 71h to the dotted-line positionsshown.

Crossing the housing 84 are two brush rotors indicated by parallel rolls92 and 93. Each roll has a brush-forming multiplicity of bristlesprojecting radially, as indicated by the numerals 94 and 95. The ends ofthe bristles of each rotor just touch or overlap the path of the ends ofthe bristles of the other rotor during rotation of the two. The rotorsare adjustable vtoward and away from each other in order to control theextent of overlap and also to compensate for wear. The extent of overlapmay be up to 3/16-inch, when the rotors are about 12-inches in diameter.

A duplicating set of rotors is shown below the rotors 92 and 93, asindicated by the numerals 92 and 93. Rotors 92 and 92 are indicated foroperation at slow speed, for example, r.p.m.,` the rotors 93 and 93 forhigh speed, for example 960 r.p.m. These relative speeds are notcritical, since speeds of l and 3600 r.p.m.-have been used, and also 5and 765 r.p.m. Where two sets of rotors are operated, the high speedrotors may be slowed somewhat over the effective high speed for a singleset, but must have speed sufficient in connection with the air streamthrough the housing to effect dispersion of the fiberous material fed tothe nip.

Also, the nature of the brush rotors may be varied. When the rotors 92and 92 are l2-inches in outside diameter, the bristles may be steel wire0.0140-inch in diameter and 3.25 inches long. When the rotors 93 and 93are 12-inches in outside diameter, the bristles may be steel wire0.0ll8-inch in diameter and 2.75 inches long. The bristles are thicklyconcentrated on the core where they are mounted, both around the rotorand along the rotor, so that at the cylindrical periphery the free endsare substantially uniformly distributed.

With two sets of brush rotors, a single drive means is provided forrotors 92 and 92', such as a driven gear 101 connected by chain 102 tothe two rotors outside the housing 84. Chain 102 passes over -adjustableidler gear 103 to permit adjustment of either or both of rotors 92 and92. For rotors 93 and 93 -a second driving gear 101 lis provided withchain 102 and idler gear 103.

Because the high speed rotor 93 or rotors 93 and 93' act as fans, thedesired generation of an air stream through the housing 84 is effectedby bafiies 105 and 106 extending downward from opposite side wallsrespectively to the vicinity of the tops of the rotors 92 and 93, thusterminating substantially at the tangent to the rotor which is at rightangles to the side wall of the housing. These baffles not only guide fedmaterial to enter the nip 107 of the top set, but cut off up-currents ofair along the side Walls beneath the baliies. Like baffles 105 and 106are positioned over the second set of rotors.

The material fed to enter the nip 107 is held by the slow rotor 92 whichslowly feeds into the nip. The fast rotor 93 combs fibers from thesupply and hurls the fibers and any material 91 away from the nip in astream of air. When two sets are present theair stream is directedtoward nip 107 of the second set, which provides additional velocity ofmovement into housing 84. .The discharged stream 110 spreads as it movestoward conveyer 74. When suction is employed, the impact of felting isgreater than without vacuum, thus making a denser felt. By control ofthe degree of suction the density of the formed felt 76 may becontrolled. Also, the adjustment of the gates 71b when using suction isanother factor for control. A

FIG. 2 is a plan View of a different set of rotors about 12-inches inoutside diameter having rigid fingersas the projecting elements. FIG. 3is a cross-section of FIG. 2 on line 3 3, showing details ofconstruction. On each of the axles 21 and 22, there is a pile of plates,alternating plates 23 with plates 24. Plates 23 are slotted circularfiat disks, with generally radial slots 25 (FIG. 3) of uniform depth ofapproximately 2 inches to provide uniformly long projecting elements 26in the form of fiatsided blades. VThe slots are about 1/z-inch apartgiving fingers of like peripheral dimension. The pla-tes 24 are spacershaving peripheries radially coincident with the bottoms 27 of slots 25.Thus, the peripheries of plates 24 extended by the bottom slots 25constitute, in effect, the periphery -of a roll or mandrel from whichthe fingers project. The plates 23 and 24 and the axles 21 and 22 havekeways for locking keys 28, vand the plates are drilled with registeringholes for a purality of holding rods 29 with tightening nuts 30, fourbeing shown. The spacers 24 are thicker than the slotted plates 23, topermit by-passing during the intermeshing indicated in FIG. 2.

FIGS. 4 and 5 show diagrammatically one use of the dispersing rolls suchas those of FIG. 2, it being understood that other forms embodying theprinciples thereof are indicated as part of the combination; FIG. 4 is aplan View of differential peripheral speed dispersing rotors 35 and 36with their axles 37 and 38 mounted in suitable frame members 39 and 40,which may be side walls of a deposition chamber shown in FIG. 5. Toillustrate means for securing differential peripheral speed,

the axles 37 and 38 outside the frame 40 are geared together and drivenby power means such as motor 41. Motor 41 drives shaft 37 bearing largediameter gear 42 meshing with small diameter gear 43 on shaft 38.

In FIG. 5, the rotors 35 and 36 are shown mounted in the upper part of adeposition chamber having said side walls 39 and 40 and end walls 45 and46. In the bottom of the chamber there is afiber-collecting member,preferably foraminous, and preferably inthe form of an endless screen 48on which to'form a felt. A suction box 49 is located under at least across-wise portion of the screen 48, which box is connected by conduit51 to a suction fan 52.

Means is provided for continuously feeding a supply of fibrous material,prefrably at a uniform rate, to the nip 54 of rotors 35 and 36. Thecharacter of such means and the character of the fibrous material mayvary Widely. A suitable form is indicated by the conveyer belt 55 overreturn roll 56 positioned .to drop fiber fiuff or fibrous elements 57into the nip 54. The belt 55 may be part of any well-known volumetric orgravimetric feeder. Discharging fibers ina vehicle of air from a conduitis another well-known method for continuously feeding a supply ofloosened fibers at a uniform rate.

As the material enters the nip 54, the rotors individualize the fibersthereof and project them downwardly in aflaring stream 57 which forms afelt 58 on the screen 48. The density of the felt may be controlled byregulating the degree of suction in box 49, other variables being fixed.Y

The speed of the rotors creates windage which is effective not only tocarry dispersed fibers away from the nip, but also to cause -the pathsof the fibers to curve generally in the direction of the two rotors,more so in the direction of the faster rotor. This effects expansion ofthe fiber stream and minimizes clotting. This expansion of the fiberstream is thus predetermined by the rotor speed. In order to controlthis expansion regardless of the speed of the rotors, one or morestreams of air may be injected into the nip along with the fibrousmaterial.

In FIG. 5 two banks of air nozzles are designated 59 and 60, each shownas having other adjusted positions 59 and 60' shown in dotted lines. Thedirections and strengths of the air jets maybe controlled to narrow orto widen the angle of dispersion otherwise resulting from the speed ofthe "rotors, and also to direct the flaring stream, more forward orrearward in relation to the direction of the moving conveyer. Thegeneration of windage by the rotors, and also the use of injected air,make it desirable to employ suction at sufiicient capacity to draw inall the air of windage and injection, and preferably more in order toprevent delivery of dispersed fiber in directions other than toward thescreen 48.

The invention is not limited to the structures described above. Forexample, the rigid fingers of FIGS. 2 and 3 may be swinging hammers,such as those found in hammer mills. Of course, for the presentinvention, they are differently assembled in the two rotors for theintermeshing described.

FIGS. 6 and 7 show one way in which this may be accomplished. Each rotorconsists of a stack of circular plates alternating in smaller and largerdiameters. One rotor is designated with axis 61, having the smaller disk62 and the larger disk 63. A plurality of tie rods 64 pass through theouter plates beyond the peripheries 65 of the vinner plates, to serve aspivotal mountings for hammers 66. The hammers 66 mounted about the axis61, extend outwardly almost to .the peripheries of the larger disk 63aon the companion rotor having the axis 61.

In order to avoid collision of opposite hammers, they are made slightlythinner than the thickness of plates 62 and 62a, and about the rods 64and 64a there are spacer rings 67 and 67a. v

The peripheral speeds of the rotors and the relative speeds thereofdepend on many factors, such as the character of the fiber supply 57,the desired rate of producing the felt, and the structure of the rotors35-36.

For example, in one case the rotors are of the type shown in FIG. 2,with slotted plates 23 12inches in diameter and 1/s-inch thick, withspacer disks 24, with the fingers 26 at l2spacing, 0.5-inch wide in thecircumferential direction and of uniform cross-section 1/2 x 1/sinches.These rotors as conveniently mounted have a speed range of 870 to 3600r.p.m., such range being the result of mechanical selections rather thanof process limitations. They are also arranged so that either one mayrotate up to three times as fast as the other. Thus, in the arrangementdisclosed in FIG. 4, when rotor 36 rotates at 2700 r.p.m., rotor 35 willrotate at 900 r.p.m.

In operation in an assembly having a deposition chamber and differentialrolls, such as shown in FIG. 5, suliite fiber is fed to the rolls at therate of about 100 lbs. per

Suction under the screen aided inV v 6 a density controlled by thedegree of impact in part predetermined by the degree of suction.

When a liquid adhesive for bond is desired, such as a starch sol, it maybe sprayed in from nozzles entering holes in the side walls of thedepositing chamber, preferably at low levels near the top of the formingfelt, in order to avoid adhesion of the side walls at higher levels,where festoons could otherwise form.

The formed mat leaving the deposition area may be removed from thescreen, provided it has strength to permit it, or vif not, it may becompressed sufiiciently to give it the necessary strength. -Suchprocessing for various uses of the felt is well known in thefiber-deposition field.

I claim:

1. Apparatus comprising two parallel generally cylindrical rotors onparallelaxes for dispersing and individualizing fibers from a supply offibrous material delivered into a nip formed by said rotors, supplymeans positioned continuouslyY to feed a supply of loosened fibers intosaid nip to be dispersed thereby, means to rotate one of said rotors onits axis in a direction to feed material through the nip, means torotate theother rotor in the opposite direction, each rotor having aninner cylindrical axial roll spaced from a corresponding cylindricalaxial roll of the other rotor, and each rotor having a multiplicity ofelements projecting outwardly from its roll, the ends of the elements ofeach roll terminating in positions substantially at the periphery oftheother roll during rotation, the elements of each rotor being arrangedin spaced peripheral alinements alternating in axial positioning fromone roll to the other so that peripheral elements of each roll travel inpaths between paths traveled bythe elements of the other roll, saidmeans for rotating the rotors being so related that only one set ofelements rakes through the other set in the direction of movement of thebrous material through the nip, whereby during rotation said one set ofelements disperses material held by the other set of elements, aforaminous fiber-collecting conveyor spaced from the discharge sideofthe nip directly to receive fibers discharged from the nip and forforming a felt thereon, means positioned laterally of the path of theloosened fibers from saidsupply means to inject at least one stream ofair into the nip of the rotors, and means providing suction on thenon-collecting side of said foraminous conveyor and having capacity todraw in at least all of the air injected into said nip.

2. Apparatus according to claim 1 in which the position of theair-injecting means is adjustable to predetermine the direction ofinjected air whereby to control the expansion of the stream of fiberdispersed by the rotors.

3. Apparatus comprising two parallelgenerally cylindrical rotors onparallel axes for dispersing and individualizing fibers from a `supplyof fibrous material delivered into a nip formed by said rotors, supplymeans positioned continuously to feed a supply of loosened fibers intosaid nip to be dispersed thereby, means to rotate one of said rotors onits axis in a direction to feed material through the nip, means torotate the other rotor in the opposite direction, each rotor having aninner cylindrical axial roll spaced from a corresponding cylindricalaxial roll of the other rotor, and each rotor having a multiplicity ofelements projecting outwardly from its roll, the ends of the elements ofeach roll terminating in positions substantially at the periphery of theother roll during rotation, the elements of each rotor being so mountedas to let pass the elements of the other rotor in rotation of the rolls,said means for rotating the rotors being so related that only one set ofelements rakes through the other set in the direction of movement of thefibrous material through the nip, whereby during rotation said one setof elements disperses material held by the other set of elements, aforaminous fiber-collecting conveyor spaced from the discharge side ofthe nip on which to gather the discharged fibers as a felt, means toinject at least one stream of air into the nip, and means providingsuction on the noni collecting side of said foraminous conveyor andhaving capacity to draw in at least all the air injected into said nip.

4. Apparatus comprising twoparallel generally cylindrical rotors onparallel axes for dispersing and individualizing libers from a supply ofbrousmaterial delivered into a nip formed by said rotors, supply meanspositioned continuously to feed a supply of loosened fibers into saidnip to be dispersed thereby, means to rotate one of said rotors on itsaxis in a direction to feed material through the nip, means to rotatethe other rotor in the opposite direction, each rotor having an innercylindrical axial roll spaced from a corresponding cylindrical axialroll of the other rotor, and each rotor having a multiplicity ofAelements projecting outwardly from its roll, the ends of the elementsof each roll terminating in positions substantially at the periphery ofthe -other roll during rotation, the elements of each rotor being somounted as to let pass the elements of the other rotor in rotation ofthe rolls, said means for rotating the rotors being so related that onlyone set of elements rakes through the other set in the direction ofmovement of the fibrous material through the nip, whereby duringrotation said one set of elements disperses material held by the otherset of elements, a foraminous fiber-collecting lconveyor spaced from thedischarge side of the nip on which to gather the discharged 'bers as afelt, independent means to injectA a plurality of streams of air intothe nip, said independent means being adjustable in position topredetermine the direction of its injected air stream, whereby saidindependent means may control the expansion of the stream of berdispersed by the rotors.

References Cited by the Examiner UNITED STATES PATENTS DONALD w. PARKER,Primary Examiner.

RUSSELL C. MADER, Examiner.

25 D. NEWTON, Assistant Examiner.

1. APPARATUS COMPRISING TOW PARALLEL GENERALLY CYLINDRICAL ROTORS ONPARALLEL AXES FOR DISPERSING AND INDIVIDUALIZING FIBERS FROM A SUPPLY OFFIBROUS MATERIAL DELIVERED INTO A NIP FORMED BY SAID ROTORS, SUPPLYMEANS POSITIONED CONTINUOUSLY TO FEED A SUPPLY OF LOOSENED FIBERS INTOSAID NIP TO BE DISPERSED THEREBY, MEANS TO ROTATE ONE OF SAID ROTORS ONITS AXIS IN A DIRECTION TO FEED MATERIAL THROUGH THE NIP, MEANS TOROTATE THE OTHER ROTOR IN THE OPPOSITE DIRECTION, EACH ROTOR HAVING ANINNER CYLINDRICAL AXIAL ROLL SPACED FROM A CORRESPONDING CYLINDRICALAXIAL ROLL OF THE OTHER ROTOR, AND EACH ROTOR HAVING A MULTIPLICITY OFELEMENTS PROJECTING OUTWARDLY FROM ITS ROLL, THE ENDS OF THE ELEMENTS OFEACH ROLL TERMINATING IN POSITIONS SUBSTANTIALLY AT THE PERIPHERY OF THEOTHER ROLL DURING ROTATION, THE ELEMENTS OF EACH ROTOR BEING ARRANGED INSPACED PERIPHERAL ALINEMENTS ALTERNATING IN AXIAL POSITIONING FROM ONEROLL TO THE OTHER SO THAT PERIPHERAL ELEMENTS OF EACH ROLL TRAVEL INPATHS BETWEEN PATHS TRAVELED BY THE ELEMENTS OF THE OTHER ROLL, SAIDMEANS FOR ROTATING THE ROTORS BEING SO RELATED THAT ONLY ONE SET OFELEMENTS RAKES THROUGH THE OTHER SET IN THE DIRECTION OF MOVEMENT OF THEFIBROUS MATERIAL THROUGH THE NIP, WHERENY DURING ROTATION SAID ONE SETOF ELEMENTS DISPERSED MATERIAL HELD BY THE OTHER SET OF ELEMENTS, AFORAMINOUS FIBER-COLLECTING CONVEYOR SPACED FROM THE DISCHARGE SIDE OFTHE NIP DIRECTLY TO RECEIVE FIBERS DISCHARGED FROM THE NIP AND FORFORMING A FELT THEREON, MEANS POSITIONED LATERALLY OF THE PATH OF THELOOSENED FIBERS FROM SAID SUPPLY MEANS TO INJECT AT LEAST ONE STREAM OFAIR INTO THE NIP OF THE ROTORS, AND MEANS PROVIDING SUCTION ON THENON-COLLECTING SIDE OF SAID FORAMINOUS CONVEYOR AND HAVING CAPACITY TODRAW IN AT LEAST ALL OF THE AIR INJECTED INTO SAID NIP.